Prostate specific antigen (PSA) testing has been the subject of much debate in recent years, with some questioning if it’s really worth the cost. But a new study suggests that without PSA testing, many more men would lose their lives.
The issue leading some people to question the value of PSA testing is that it can detect tumors that are so tiny and so slow growing that they would never really require treatment or pose any real risk to a person’s health. Other prostate cancers, of course, can be quite serious, and these need to be removed before they become fatal.
Using the data from the 1980s, they estimated the number of metastatic cancers that would have occurred in 2008 if screening had not been done. The number they came up with was about 25,000, or over triple the number that actually occurred.
To gauge what the situation would look like if the PSA test didn’t exist, researchers compared data from the mid-1980s, when PSA testing was not routine, to data from the mid-2000s, when it had become commonplace. They paid special attention to serious forms of the disease which had become metastatic – spread to other parts of the body.
This is a sizeable difference, and suggests that we should not be so quick to drop the screening – especially since metastatic cancers are often fatal.
"Our findings are very important in light of the recent controversy over PSA testing," said study author Edward Messing in a news release. "Although there are trade-offs associated with the PSA test and many factors influence the disease outcome, our data clearly indicate that not doing the PSA test will result in many more men presenting with far advanced prostate cancer. Almost all men with clinically apparent metastases at initial diagnosis will die from prostate cancer.”
According to another new study, which may also support the use of PSA tests, men who have prostate cancer are now much less likely to die from the prostate cancer itself. In fact, men with prostate cancer are more likely to die from other, often preventable conditions like heart disease. The researchers say that the difference is likely due to the fact that PSA is detecting prostate cancer much earlier on, when it has the greatest likelihood of being treated. Unfortunately, the lifestyle factors that can prevent other causes of death (not smoking, eating the right amount, and exercising) are not being observed so well, leading the researchers to recommend that doctors use prostate cancer diagnosis as a “teachable moment” to focus on healthy habits.
Where PSA testing will be in the next decade is unclear at the moment, but there is no doubt that it saves many lives as it is used today. Whether we can find the right balance point between treatment and overtreatment is really the central question.